Double-acting pump



` APl' 27, 1948 .L ro LEONARD l lZAIMAIL DOUBLE ACTING PUMP.

Filed mb.. 1.5'g 194@ 3 Sheets-Sheet 1 J. T. LEQNARD DOUBLE ACTING PUIP Filed Feb. 15, 1946 April 27, 1948.

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DOUBLE ACTG PUMP Filed Feb. 155. 1946 5 Sheets-Sheet 3 Patented Apr. 27, 1948 UNITED STATES PATENT GFFICE DOUBLE-ACTING PUMP John T. Leonard, Evanston, lill. Application February 15, 1946, Serial No. .647,769

(Cl. 18d- 28) ii Claims. 1.

This invention relates to a doub1e-acting pump designed for use in a lubricant distributing system.

One object of the invention is to provide a simple and durable pump structure adapted for economical manufacture.

Another object of the invention is to provide a lubricant pumping unit with valve mechanism incorporated therein by which the unit-is `adapted for use in a reversible system arranged to lubricate a plurality of bearings connected in the system.

it is also an object of the invention to provide e. lubricantJ pumping unit for periodically supplying lubricant to a group of bearings, and to provide at the pumping device a pressure responsive indicator to show when the lubricant has reached all the bearings of the group.

@ther objects and advantages of the invention will appear from the following description, taken in connection with the drawings, in which:

l is a vertical sectional view of a double acting lubricant pump embodying this invention -nd taken substantially as indicated at line i-i Fig. 2;

2 is a horizontal sectional view of the pump taken substantially as indicated at line iik-2 in Fig. l

3 is a transverse vertical section taken substantially as indicated at line 3*?) in Fig. 2; and

is a detail sectional view 'taken substam tially as indicated at line in Fig. 2.

The pump which is the subject matter oi this invention is intended particularly for use in 'a lubricating system of the type in which a plurale ity or metering valves or control valves for individual bearings of the systern are connected between a pair of feed lines which are supplied alternatively with lubricant ied into the system at intervals from the pump; the metering valves a e so arranged that the system is reversible, the lubricant being ted to the valves from one supply line until all valves of the system have been actuated to supply lubricant to hearings connected with them, and the flow being then, or at subsequent operating period. shifted so as to cause the valves to be operated by lubricant from the other line either lor lubricating the same bearings or for feeding lubricant to a second group oi bearings connected to the same valves.

,Distributing valves of this character are described in Patent #2,260,497 to John B. Whitted, dated October 28, 1941, being shown in Figures 20 to 24, inclusive, therein.

with a pair or" As shown in the drawings, the pump structure is mounted in a hollow base iii having an upstanding ange i2 in which there is secured a tank or reservoir it for the lubricant to be distributed by the pump. rl`he tank it is provided with. the usual follower piston it having a piston rod i8 which extends slidably through the top wall 2li of the tank to serve as in indication of the quantity of lubricant remaining therein. The base iii has projecting from it a iitting 22 adapted for connection with a hose or pipe through which lubricant may be supplied for nlling the tanlt it, and inside the base lll the litting feeds through a cylindrical screen 24 which is secured between an opstandingv lug 2@ and the threaded annular portion 28 oi the ltting 22 .vhicn is screwed into the side wall 0iJ the base A. sump or supply chamber fili is formed in. the

f base by partitions cast integrallytherewith,

this chamber being in open communication with the lower end of the tank ifi. A casting 3i? secured in the bottom wall of the chamber 3G and forming portion of said bottom wall, is provided ertical bores 3G, iid which are counterbored and threaded at their upper ends to receive the cylinders 3G, El@ oi the pump. Each oi said cylinders is provided with a piston Sill reciprocable therein, and said pistons are arranged to be actuated alternately by cam arms dil, .it extending from opposite sides ci a hub which is xed to an operating shaft dil. 'lne base includes integral bearings it? and .18 :for said shaft fit, and outside the base the shaft is bent at right angles to provide a handle portion Freierably the shaft emerges from the base to through a studng box and it is retained in its bearings by means oi a set screw having its inner end portion engaged in a groove 5G in the shaft. The inner end of the shaft is flattened on one side at and the hub l2 is similarly formed for interengagement therewith. The upper end portion of each of the pistons Si? is formed with ano-tch which embraces one or the cam arms thus providing positive drive connections by which the rocking of the shaft ill serves to reciprccate the pistons in opposite directions.

Each of the cylinders E@ has inlet ports 2 which communicate with the interior oi the sump or chamber 3Q so that as each piston reaches the upper limit of its movement, it uncovers the inlet ports t2 and admits a charge of lubricant to the cylinder. At its lower end each cylinder is provided with a ball check valve 64 normally seated by a spring E@ and adapted to be forced 3 open by the downward stroke of the piston 38 to admit lubricant from the cylinder to a. passage 66 formed in the casting 32.

The passage 68 intersects a bore 18 in the casting 32 in which there is fitted a slide valve 12 havin-g a reduced portion 14 which provides an annular space 16 vcommunicating at all times with the portions of the passage 68 extending from both cylinders 36, 36. Thus the lubricant is first expelled from one cylinder and then from the other into passage 6B. When the valve member 12 is positioned as shown in Figure 1, the

space 16 communicates with an outlet port 18 i connect with a passage 86 extending axially in said valve member 12 and opening through one end of said member into a chamber 88 at the end of the bore 18. A port 98 in the wall of the chamber, 88 is connected by a pipe 92 with a sump or chamber 38, as seen in Figures 2 and 3, In order that the pressure of the lubricant fed through the outlet port 18 and pipe A shall be effective to actuate the metering valves, any opposing pressure upon the valve must be relieved; such relief is afforded by way of the return pipe B which opens freely into the chamber 38 It should also be understood that all parts of the valves are kept normally lled with lubricant and that when the valves are actuated some of this lubricant is displaced and is fed back through the pipe B -to the chamber 38. To feed the lubricant through the system in this manner, the operating handle 58 is rocked back and forth repeatedly to actuate both pistons 38 so that lubricant is fed alternately from the cylinders 36 into the pas-v sage 68 and to the outlet 18.

In some arrangements each distributing or metering valve of such a system serves two bearings; accordingly when one series of bearings has been lubricated as just described the ilow of lubricant is reversed through the system to serve the remaining bearings. In other cases each metering valve serves only one bearing but is arranged so that lubricant is fed to the bearing when pressure is applied to the system in one direction, and is again fed to the bearing when pressure is applied in the opposite direction. If the pump unit of this invention is employed in a system of the rst type, the valve 12 will be shifted immediately after the lubricant'has fully traversed the system in one direction, and the pump will then be operated to feed lubricant in the opposite direction, that is, through the port 88 and pipe B to the valves, with pipe A serving as the return passage to the sump 38. If the system is of theY second type described, the valve 12 will be shifted only' at the yintervals at which relubrication is required by s the bearings of the system.

The manually operable lever 94 engaged with the valve member 12 may be actuated to shift it to the position shown in Figure 2, in which the space 16 connects the passage 68 with the port 88 while a groove 96 in the valve member registers with the port 18. With the valve in this position. the lubricant discharged from the pump cylinders '4 36, 36 iiows out into the system through the port 88 and returns by way of the port 18. The groove 96 is connected by ports 98 with the axial passage 86 in the valve member 12, thus providing for discharge of the return flow into the chamber 88 at the end of the bore 18 and thence into the sump 38 by way of the pipe 92. A spring pressed ball detent |88 is engageable with a, groove |82 when the valve 12 is shifted to the first position above described, and engages in the groove |84 in the valve member when the latter is shifted to its second described position, as shown in Figure 2.

It may be understood that in systems of the type for which this pumping unit is intended the lubricant which is fed under pressure through the pipe A to the metering valves is not discharged directly therefrom to the bearings to be lubricated but is utilized to shift certain movable parts of the valves and ls then stored in said valves until they are next actuated by pressure applied through the pipe B. Accordingly, when all the valves of the system have been operated and illled with lubricant furnished through the pipe A, there is no place for additional lubricant to go; therefore, continued operation of the pumping pistons 38, 38 will tend to build up the pressure rapidly in the pipe line A and passage 68.

A short continuation of the passage 68, denoted at 69 in Figures 3 and 4, is connected by a tube 1| with an indicator which comprises a cylinder 13 with a plunger 'l5 slidable therein, and a reduced portion or stem 11 on the plunger exposed at the end of the tube 1|. A spring 19 resists outward movement of the plunger but upon the application of suicient pressure to the tube 1I said spring is overcome and the plunger protrudes to the dotted line position indicated at 15a in Figure 4. The spring 19 may be made strong enough to resist the maximum pressure which it is considered may be necessary to feed lubricant to the bearings by operation of the metering valves-about 2000 lbs. per square inch-and when this pressure is exceeded in the pipe line A and passages 68 and 69 the indicator plunger 15 will be operated as described. When the pumping action is discontinued, the pressure in the passage 69 and tube 1| will subside or will be relieved immediately upon reversal of the valve 12 and thus permit the indicator plunger 15 to return to its normal position. l

Before the pump is again actuated, the valve 12 will be shifted by means of its hand lever 94 so that the next operation of the pump will feed lubricant under pressure through the port 88 and pipe line B. This will have the eiect of shifting movable parts in the metering valves to expel the lubricant stored therein from the previous operation, thus feeding such lubricant in suitably measured quantities to individual bearmum amount of machining for finishing principal parts. The hollow castbase |8 will require only the finishing of the bearings 46 and 48 for the rock shaft 44 and the tapping of a hole for the threaded inlet fitting 28, except that the underside of the sump 38 will be drilled and tapped as indicated at |06 in Figure 2 to receive screws by which the cast block 32 is attached. Practically all the precision work required is concentrated in the block 32 which includes the bore It for the valve 12, the communicating ports 78 and 8l) and a suitable opening for the spring detent Iii. This block also includes the openings 35i in which the cylinders 36 are secured and the aligned threaded openings ior the hollow caps Hi8, |68 in which the check valve springs $6 are seated. The passage 68, t@ is drilled to intersect the bores 34 and is threaded at its outer end to receive a vent fitting lili having a needle valve with a inurled head Ii2 by which 'the valve lmay be opened occasionally to relieve any air pressure which may be trapped in the pump.

While there is shown and described herein certain structure embodying the invention and illustrative thereof, it is to be understood that the invention is not limited thereto or thereby, but embraces all changes and modications in its various features which may come within the scope of the appended claims.

I claim:

l. In a pump oi the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion oi the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore. said block having ahorizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member vmovable in said horizontal bore to connect the outlet bores alternatively with said transverse bore. and a piston reciprocable in said cylinder.

2. In a pump oi the class described, a hollow base casting which includes an. upwardly open sump, a block ntted into and forming a portion or the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion ltted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair o outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, said valve member having a longitudinal passage with lateral ports positioned to connect said passage to said outlet ports alternatively, the longitudinal passage fof the valve member opening into the horizontal bore, conduit means connecting a portion of said horizontal bore with the sump, and a piston reciprocable in said cylinder.

3. in a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a pair ol? vertical bores threaded at their upper ends, a pair of pump cylinders having their lower end portions fitted into said bores respectively and each having a threaded portion engaging the upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting both said vertical bores with the horizontal bore, said block having also a pair of outiet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet ports alternatively with said transverse bore and a-pair'oi pistons reciprocable respectively in said cylinders, to-

gether with a rock shaft journaliedin said hollow base and cams thereon engageabie with said pistons for actuating them.

4. In a pump ol' the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wail of said sump, said block having a vertical bore threaded at its upper end, a pump 'cylinder having its lower end portion tted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal 'bo-re and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, a piston reciprocable in said cylinder, together with a pressure indicator comprising a cylinder mounted in a wall of said hollow base, a plunger having a portion adapted to be protruded from one end o. the cylinder, spring means yopposing such protrusion of the plunger, and conduit means through which the pressure developed in said transverse bore is applied to the other end of said plunger.

5. In a pump o the class described, a hollow base casting which includes an upwardly open sump. a block ntted into ,and forming a portion of the bottom Wall oi said sump, said block having a pair or vertical bores, a hair of pump cylinders having their lower end portions fitted respectively into said bores, said block having a horizontal bore disposed midway between the lower end portions of said vertical bores and a transverse bore which intersects said horizontal bore and both vertical bores with a portion of said transverse bore extending beyond one of the vertical bores, said block having also a pair oi outlet ports intersecting the horizontal bore at longitudinally spaced portions thereof, a slide valve movable in said horizontal bore to connect said outlet ports alternatively with said transverse bore and the cylinder, a pair of pistons reciprocable in said cylinders, a check valve for each cylinder at its lower end, said cylinders having lateral inlet ports exposed in the sump, and a pressure indicator connected to said extension of the transverse bore for response to the pressure developed therein.

6. in a pump oi the class described, a hollow base casting which includes an upwardly open sump, a block iitted into and forming a portion of the bottom wall ci. said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore, said bloeit having a horizontal bore and a transverse bore connecting said vertical and horizontal bores. said block having also a pair oi outlet ports which intersect said horizontal bore, a slide valve member movable in sai-d horizontal bore to con- 4neet the outlet bores alternatively with said transverse bore, a piston reciprocable in said cl/ln inder, said cylinder extending upwardly into the sump and having a lateral inlet port exposed therein and uncovered by the piston at the upper limit of its reciprocation.

'7. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block tted into and forming a portion of the bottom wall ci said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion iltted into said bore and having a threaded por- .M orts which intersect said horizontal bore, a slide valve member mov'able in said horizontal bore to connect the ,outlet bores alternatively with said transverse bore, a piston reciprocable in said cylinder, together with a ball check valve seating n upwardly against the lower end of said cylinder, the lower end of said bore in the block being threaded and a hollow threaded cap secured therein with a spring for the check valve pocketedv in said cap.

8. In a pump of the class described, a. hollow base casting which includes an upwardly open sump, a block tted into and. forming a portion of the bottom wall of said sump, said block having a pair of vertical bores, a pair oi.' pump cylinders having their lower end portions fitted respectivcly into said bores. said block having a horizontal bore disposed midway between the lower end portions of said vertical bores and a transverse bore which intersects said horizontal bore and both vertical bores with a portion of said transverse bore extending beyond one of the vertical bores, said block having also a pair of outlet ports intersecting the horizontal bore at longitudinally spaced portions thereof, a slide valve movable in said horizontal bore to connect said outlet ports alternatively with said transverse bore and the cylinders, a pair of pistons reciprocable in said cylinders, and a manually operable air vent valve in said extension of the transverse bore and accessible outside the hollow base.

- l JOHN T. LEONARD. 

